Haseo

ハセヲ

In .hack//Roots, Haseo is a novice player in the online game known as The World. He is an outcast in real life and struggles with social interactions. Upon logging into The World R:2, Haseo is attacked by PKs (Player Killers) and rescued by Ovan, the Guild Master of the Twilight Brigade.
Haseo joins the Twilight Brigade to learn more about Ovan. Eventually, after Ovan disappears for an extended period, the Twilight Brigade is disbanded and Shino is PKed by Tri-Edge. Obsessed with saving Shino, Haseo continually seeks power, culminating in his journey into the Forest of Pain, a new Lost Ground. There, after confronting another AI, Harald, his PC body is transformed.
At that point, level 133 and equipped with an arsenal of incredibly powerful weapons, Haseo becomes the Terror of Death, a PKK (Player Killer Killer) who hunts down Player Killers. Upon finding them, he demands information on Tri-Edge; if they fail to provide any useful information, which is usual, he kills them. The name Terror of Death is the title given to him by players, as he truly cares nothing for any other player except for Shino.
Around this time, Ovan returns and informs Haseo that Tri-Edge will reappear shortly at the Hidden Forbidden Holy Ground. Haseo attempts to defeat Tri-Edge but is Data-Drained, returning some time later as a level 1 character with no items or contact info.
(AIDA - a bug in [the] that, when normal players come into contact with this 'bug', causes their data to be altered/corrupted; if AIDA doesn't just infect the player, the player will fall into a coma)
(Ephitaph users - a select few with Avatars used to fight against Tri-Edge and AIDA among other 'bugs' or 'threats')
(Avatar - a total of 8 creatures first seen in the original DotHack where Kite and his friend defeated them all; Avatars are now used by the Ephitaph users to 'delete' the bugs called AIDA or to remove these bugs from infected players; Avatars use a special move called data drain that, when used on players without an Avatar or AIDA inside them, causes them to drop into a coma).
While it is never officially announced whether they are the same person or not, Haseo has the same real name and is close to the same age as the player of Sora from .hack//sign, as well as sharing a connection to Skeith.